Let $\mathrm{E}_{1}, \mathrm{E}_{2}, \mathrm{E}_{3}$ be three mutually exclusive events such that $\mathrm{P}\left(\mathrm{E}_{1}\right)=\frac{2+3 \mathrm{p}}{6}, \mathrm{P}\left(\mathrm{E}_{2}\right)=\frac{2-\mathrm{p}}{8}$ and $\mathrm{P}\left(\mathrm{E}_{3}\right)=\frac{1-\mathrm{p}}{2}$. If the maximum and minimum values of $\mathrm{p}$ are $\mathrm{p}_{1}$ and $\mathrm{p}_{2}$, then $\left(\mathrm{p}_{1}+\mathrm{p}_{2}\right)$ is equal to :